1. Field of the Invention
This invention relates generally to adjustable wrenches, and particularly to an improved positive locking action for an adjustable wrench so as to permit the jaws of the wrench to be preset to a desired opening measured with an associated scale and then locked positively so as to prevent the movable jaw from moving relative to the fixed jaw of the wrench.
2. Description of the Prior Art
It is known generally to provide adjustable wrenches which employ eccentrics which pivot about an axis transverse to the longitudinal extent of the wrench in order to bring locking teeth associated with the frame of the wrench into engagement with mating teeth provided on the movable jaw of the wrench. Examples of such arrangements can be found in U.S. Pat. Nos: 1,038,671, issued Sept. 17, 1912, to E.J. Spink; 1,451,906, issued Apr. 17, 1923, to I. C. Gellman; and 3,376,766, issued Apr. 9, 1968, to D. Vienat. A spring is normally employed with such locking devices in order to bias the member pivotally mounted on the frame of the wrench toward a position in which the mating teeth are engaged.
Other examples of adjustable wrenches which selectively engage teeth provided on the movable jaw of the wrench in order to lock the movable jaw in a predetermined or preset position can be found in U.S. Pat. Nos: 1,206,947, issued Dec. 5, 1916, to W. S. Upson; 1,436,049, issued Nov. 21, 1922, to J. F. Oliver; 1,539,987, issued June 2, 1925, to J. A. Bell; and 3,286,561, issued Nov. 22, 1966, to E. M. Norman.